Which of the following is not a Boolean attribute for <audio> element?
a) autoplay
b) loop
c) muted
d) buffered

Answer: d
Explanation: Autoplay is a Boolean attribute and its default value is set as false. Basically, this feature of autoplay is avoided due to the unpleasant experience of users. Loop is also a Boolean attribute. Muted is Boolean attribute whose value is set as false by default. Buffered is not boolean attribute in <audio> element.